This invention relates to apparatus for variably adjusting the magnetic level of a system with a translating spring force, and, in particular, to multipole circuit breakers wherein the magnetic levels of the poles are simultaneously adjusted by varying forces of extension springs associated with respective armatures. Accordingly, it is a general object of this invention to provide new and improved apparatus and circuit breakers of such character.
Generally, in the past, the magnetic trip level of circuit breakers were not variable or adjustable. Thus, since circuit breakers were produced to "standard" conditions, separate selected circuit breakers were required for selected magnetic levels.
Specifically, it is believed that at least one manufacturer offers for sale circuit breakers having adjustable magnetic trip levels by virtue of adjustable gaps. Some such device uses a comparatively large variable gap of 600 to 800 mils.